On Mon, May 4, 2015 at 4:11 AM, Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> wrote: > Hi Octavian, > > On 04/27/2015 07:23 PM, Octavian Purdila wrote: >> >> On Tue, Apr 28, 2015 at 12:57 AM, sathyanarayanan kuppuswamy >> <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> wrote: >>> >>> Hi >>> >>> On 04/27/2015 08:54 AM, Octavian Purdila wrote: >>>> >>>> On Mon, Apr 27, 2015 at 6:42 PM, Kuppuswamy Sathyanarayanan >>>> <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> wrote: >>>>> >>>>> Since Acpi framework already exports this info to user space, Why not >>>>> do >>>>> this derivation in user space code ? Why do we need new ABI, if the >>>>> same >>>>> can be derived from existing one. >>>>> >>>> The ABI was added in the previous patch so that we can present the >>>> sensor orientation information to userspace even in the case of device >>>> tree. >>> >>> If the main reason for implementing a new ABI is to support DT platforms, >>> Why not implement a version of _PLD for device tree ? Don't you think it >>> would be much better than adding a new ABI to export redundant >>> information ? >>> >> IMO the mounting matrix is more consistent with the IIO ABIs. Although >> I have no issue with repicating _PLD for device tree if people agree >> that it is better. > > Since your main issue is, device tree lacking ABI to specify location > information, you should consider fixing it there. Let's wait for others > comment on this. > > If you think mounting matrix provides more information than what is > supported > by _PLD, then we should consider implementing another ABI. AFAIK, that is > not > the case here. > > Adding adding a new ABI to represent the information that can be derived > from existing ABI does not seem to be useful. AFAICS the ACPI _PLD information is not (yet) exported to userspace. This patch: http://marc.info/?t=140795040700003&r=1&w=2 does not seem to be merged upstream. So there is no existing ABI to derive from :) >> >> >>> Also the location information of the device is not just specific to iio >>> drivers. You should consider that we would have similar requirements for >>> devices implemented as input or platform drivers. >> >> The upstream standard for those sensors where the orientation matters >> (accelerometer, gyro, compass) is IIO. >> >> Granted, there are other device types for which the orientation >> information may be useful (e.g. camera). However the actual >> interpretation and action to be taken is different for each subsystem >> (e.g. in the camera case do the correction via V4L2_CID_HFLIP / >> V4L2_CID_VFLIP) so I think it is better to expose it at the subsystem >> level in a way consistent with the subsystem's ABIs. > > I agree that location information is used differently at different > sub systems. But my question is why we need a new ABI ? > > Why not handle it in user space ? > > - -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
